# 可变类型：列表，字典
# 不可变类型：int、float、string、tuple
a = 2
b = 2
c = a + 0
c += 0
print(id(a), id(b), id(2))
print(c is b)

lis = [1, 2, 3]
lis2 = [1, 2, 3]
print(lis is lis2)
print(id(lis), id(lis2), id([1, 2, 3]))
